A review of local-scale agricultural sustainability in the coffee regions of Mexico

J. Gómez-Velázquez, A. Vásquez-López, J. Regino-Maldonado, and S. N. Jurado-Celis. 2023. A review of local-scale agricultural sustainability in the coffee regions of Mexico. Int. J. Agric. Nat. Resour. 23-45. The concept of sustainability aims to integrate diverse aspects of human needs through the analysis of the environmental, social, and economic dimensions. Although there is a marked consensus on the concept of sustainability, there are local conditions that define the production patterns and their actual sustainability conditions. This paper aims to integrate a research review of sustainability in the agriculture systems of Mexico with a local-scale approach, highlighting the local perspectives of each region to provide a clear view of the whole country’s agriculture systems and to find the thresholds of sustainability research in the coffee regions of Mexico. To integrate the review, several databases and quotes from selected papers were used from 2012, with some baseline references from 2002, and the paper structure was developed under a narrative technique. As a result, we show a view of the sustainability research approaches at different local scales in the agriculture systems of Mexico, emphasizing coffee systems and showing the thresholds of sustainability research with these approaches.


Introduction
The scientific foundations of the concept of sustainability have generally been ascribed to the Brundtland Report in 1989. This concept has evolved through the international discourse toward the reduction of the environmental impacts and the point of assuring "the future generations to meet their needs (Brundtland, 1987). The concept of sustainability comes from environmental criticism foundations, which turned into action proposals in public policies and agreements worldwide.
The 2030 Agenda for Sustainable Development stimulates actions in areas of critical importance for humanity and the planet (UN, 2015). The 2030 Sustainable Development Goals (SDGs) illustrate the ways in which agriculture, particularly food value chains, is positioned to holistically address the social, economic, and environmental dimen-sions of sustainable development and represents a base for fostering sustainable economic growth, reversing harmful environmental trends, and enhancing resilience, tracing some of the most potent pathways for agriculture policies (Omilola & Robele, 2017).
While sustainability assessment is a growing concern worldwide, with United Nations' Agenda 2030 being implemented as it considers the environmental, social and economic issues in light of cultural, historic and institutional perspectives, appropriate tools are needed to ensure the complete coverage of these aspects (Villeneuve et al., 2017). On the other hand, the agroecology perspective seems to be an alternative to reach the 2030 Agenda objectives, as it can effect systemic change, which is needed to provide sustainable food for everybody, as stated in the Agenda (Ching, 2018).
The sustainability assessment from agroecology focuses on the definition of a degree of sustainability with participatory methodologies and a multidisciplinary approach of the production units in a certain context (De Ataide et al., 2015). Sustainability programs such as the Assessment Framework for Management Systems with Sustainability Indicators (MESMIS) aim to evaluate production units as agroecosystems according to their sustainability threshold (Jiménez-Ortega et al., 2022).
The sustainability assessment from the agroecology perspective allows the evaluation of multidimensional variables of the production units to establish a degree of sustainability based on their local approaches with participatory methodologies. This is important for linking the theoretical assumptions to the local realities (Astier et al., 2012).
As coffee production has been designed as an example of sustainable production (Perfecto & Vandermeer, 2015), it is important to highlight the sustainability research on these particular agriculture systems to illustrate a good example of sustainability from the sustainability perspective in the Latin American context. To properly illustrate the differences among regions, we performed a review by regions of our country (Mexico) as an example of the perspectives and heterogeneity of studies related to sustainability. This is why this paper aims to explore the background of sustainability research from several concept applications within the Latin American context with local-scale examples and experiences in agriculture systems. Then, explain particularly those of coffee production. This paper contributes to the sustainability perspective in agriculture studies with an emphasis on coffee systems.

Search Methods and Inclusion Criteria
To build this review, we used several databases: Dialnet, SCielo, Redalyc, JSTOR, ScienceDirect, and Scopus. Not only were the reference lists in several papers used to integrate the background, but the paper quotes found in Google Scholar replying to baseline papers were also used.
In the review, there were included papers from 2012 to date with some baseline papers in the period 2002-2012. Only indexed or at least peer-reviewed articles and a few relevant thesis documents (only those found by Google Scholar quotes) in Spanish, English and Portuguese were considered.
Papers with both qualitative and quantitative scopes were integrated into the discussion. The references were ordinated by the regions of Mexico, even for sustainability agriculture studies in general and those of coffee systems in particular. No criteria were used to evaluate the validity of the studies.
To summarize this literature review, a simple narrative technique was used to express the findings and the regions of Mexico, and the emphasis on coffee production allows us to appreciate the heterogeneity among different regions as well as the performance of a so-called agriculture system with high potential for sustainability: coffee.

Sustainability: From the concept to the localscale realities
There is a large difference between the global perspectives of sustainable development and those of the local communities trying to perform it. It is important to take participatory approaches, setting the context for sustainability assessment at local scales (Reed et al., 2006).
While the most common definition of sustainability lies at the intersection of environmental, social, and economic dimensions (Elkington, 1997), there is also a marked difference between sustainable development and sustainability concepts, and the significance of the distinction will depend on one's perspective.
According to Clift (2003), the concept of sustainability can be referred to as the process of achieving sustainable development. Therefore, Sikdar (2003) suggests that the metrics of sustainability allow quantification in the realization of sustainable development.
Within the discussion on the economic perspectives of development, there was a notion that environmental and developmental issues did not merge strongly (Mebratu, 1998). Since the World Conservation Strategy was formulated in 1980, the concept of sustainability has been brought into this debate. Then, the operation, quantification, and variable treatment of the sustainable development approach seem to be executed under the concept of sustainability, but with the element of time within the environment and development discussion, it was possible to synthesize what was previously a diffuse idea of sustainable development (Khosla, 1995).
In contrast to the fields of application of the sustainability concept, some researchers have focused on the endorsement of the environmental concept of sustainability within the empirical scopes in production research (Sarkis & Zhu, 2018), even from the business corporate perspective (Lozano, 2015), as well as for performance in manufacturing companies (Harik et al., 2015). Moreover, there is a rising concern about the biophysical and social measurement of climate change within sustainability issues (Fenichel et al., 2016).
On the other hand, researchers look to explain local sustainability programs by linking the theoretic framework to empirical models (Owen & Videras, 2008), even considering communitybased resource management with a cultural and community approach (Keitumetse, 2014), proposing locally adapted projects (Winther, 2017), or applying sustainability assessment frameworks to local-scale cases (Jiménez-Ortega et al., 2022). Dietz et al. (2018) suggest that there are normative, methodological, and philosophical considerations in choosing a certain definition of sustainability. There are also local conditions that need to be comprehensively analyzed to obtain a holistic view of sustainability in specific locations (Ravichandran et al., 2021).

The Voluntary Sustainability Standards (VSS)
is an example of a sustainability assessment framework of agriculture from the certification standards perspective, of which recent findings suggest that the best practices in conducting robust evaluations for addressing sustainability trade-offs and measuring environmental outcomes could be improved through credible research measuring VSS impacts (Traldi, 2021).
On the other hand, the Framework for Evaluation of Management Systems with Sustainability Indicators (MESMIS) represents a baseline to perform participatory methodologies in local contexts to assess agriculture systems in terms of sustainability (Jiménez-Ortega et al., 2022).
In sustainability studies, heterogeneity comes to the fore as a generalized condition of rural com-munities (Winther, 2017), producers and growers in rural agriculture (Guadarrama-Zugasti, 2008), and membership heterogeneity in sustainability cooperatives (Elliott et al., 2018). Even in welldemarcated contexts, there is heterogeneity among social, economic, and environmental conditions. Particularly in rural community contexts, multiple interpretations and weak definitions of sustainability lead to confusion and misunderstanding among both researchers and local people. Some proposals have tried to integrate holistic sustainable place-based rural community models to measure community sustainability particularities and illustrate this heterogeneity (Winther, 2017).
However, there are many different ways to define sustainability, even from philosophical, ideological or methodological aspects. At this point, the sustainability assessment comes to the fore to propose a multidimensional approach to evaluate agricultural systems (Pashaei Kamali et al., 2017). From this perspective, we have taken the concept of sustainability as the property that allows an agricultural system to maintain its permanence over time (Khalili et al., 2013).
Even though there are sustainability concepts and assessment tools formulated under certain conditions for methodological purposes, we consider that there are also heterogeneous local conditions that complicate sustainability assessment, measurement, and analysis. This is why we discuss in this paper a view of the Latin American sustainability perspectives in the case of Mexico, with an approach by regions to highlight this heterogeneity and the particular case of coffee systems that have shown potential for sustainability.

Local-scale sustainability: The importance of community-based practices and culture
To introduce to our local-scale approach of sustainability, we lead this discussion to the current conditions of environmental conservation, the perceptions of the local people and the importance of community-based practices.
The pressure on ecosystems within human-environment interactions creates a high vulnerability context. According to Eakin & Wehbe (2009), farmers' efforts to address their vulnerability can have implications for the sustainability of the social-environmental system.
Although more than 8.5 billion hectares of land around the world are property of rural communities under customary use and administration, there is no official recognition from formal laws (Wily, 2011). Some authors suggest that communitybased resources reduce impacts on ecosystems (Barsimantov & Kendall, 2012), and in particular, those under proper indigenous community land management show the lowest ecosystem impacts (Nolte et al., 2013).

The indigenous population is significant in Latin
America since it consists of approximately 50 million people who belong to 500 different ethnic groups. The largest populations (in absolute and relative terms) are in Mexico, Guatemala, Peru, and Bolivia (De Dios, 2020). In Mexico, approximately 92 percent of small farms are owned by indigenous community members (Jaffe, 2008).
Indigenous communities have articulated ideas of communal stewardship over land and a deep spiritual and emotional connection with the earth and its fruits (Anaya, 2005). To explore the meanings of nature, land, and sustainability in indigenous communities, it is necessary to acknowledge the traditional meanings of land, nature, and sustainability from their experiences, culture, and customs (Datta, 2015).
Since sustainability and development seem to be opposite terms, Martínez-Luna (2003) recognizes this diametrical antagonism under the premise that, despite their resistance, indigenous communities have learned to integrate the aspects of development into their culture as a manner of adaptation.
The New Community Rurality approach focuses on the economic-ecological conditions of rural communities to explain sustainability in the socioenvironmental context of Latin America. Peasant practices include heterogeneous processes of social appropriation of nature, and community-based sustainable resource management can be driven under communality principles (Fuente-Carrasco, 2009).
The commonality concept rises as a philosophical construct to integrate the community social dynamics performed over centuries and transmitted via oral tradition in the indigenous language. This way of organization based on an indigenous worldview has its essence, identity, and sense of belonging within a metaphorical sense of autonomy (Guerrero-Osorio, 2015), which is an expression of rituality.
The rituality in indigenous agriculture has been the foundation of agricultural cycles and materials in this kind of community (Romero-Contreras, 2004). Rituals have been described as an essential part of the culture, ideology, and relationship with the environment for agricultural activities (González-Jácome, 2003). Community embeddedness, identity, communality, and worldview contribute to sustainability as well as entrepreneurial projects (Molina-Ramírez & Barba-Sánchez, 2021). Community values, beliefs, and knowledge promote local sustainability and represent an opportunity to develop an adapted view of sustainable development (Vásquez-Arango et al., 2016). Community perspectives have been recognized as a way of transition to be contemplated within national legal frameworks for agroecology purposes (Domené-Painenao et al., 2015). Certain proposals, such as indigenous knowledge systems, have been proposed to express significant values and traditional knowledge to applicable strategies for local agricultural activities (Enock, 2013).
From community-based initiatives to theoretical community-based frameworks, there are expressions of community sustainability that are potentially applicable to agricultural system approaches. To develop sustainable agricultural practices and reach an adapted view of sustainability, it is necessary to have a local community perception and further investigate the agricultural system and its local context. Duxbury & Jeannotte (2010) argue that the link between culture and sustainability comes from even conceptual and policy discourses, and cultural facts serve to develop planning frameworks not only in rural contexts but also in developed economies and societies. A research gap is found in tools suitable to the local context in developing countries such as Mexico, where data and skills availability could differ greatly between regions and municipalities (Calleros-Islas, 2019).
In the next section, the perspectives of agricultural production for sustainability issues in Mexico are shown. From the common characteristics to the heterogeneous ones, from the northeast to the southeastern regions of Mexico, the sustainability of agriculture and particularly of the coffee systems studies in Mexico is explained.

Sustainable agriculture in Mexico: A localscale review
There is a wide difference between the geographic regions of Mexico in terms of socioeconomic factors and indigenous or nonindigenous populations (Rivera et al., 2003), where the north-south contrast comes to the fore in national terms. Even in a country, the conditions for sustainability are diverse. Therefore, we present a review of agricultural sustainability research along the regions of Mexico and highlight the main characteristics of each region.
Recent studies in Nuevo Leon are looking to develop waste management to reduce agroindustry impacts (Escalera-Chavez et al., 2015) as well as to orient farmers toward agro-industrial processes for a productive program and competitive conditions with a sustainable focus (Pantoja-Zavala & Flores-Vichi, 2018).
Particularly in the southeast region, research has recently focused on criticism of the industrialized food system and alternatives for local conditions. Bellante (2017) suggests that alternative food networks represent a livelihood strategy for the community economy, sustainable food governance from organic agriculture, and local commodity chains. There is also an idea of the heterogeneity of agricultural producers in context, where their attitudes, opinions, preferences, objectives, and risk perceptions have been analyzed (Sánchez-Toledano et al., 2017).
From the arid and industrialized north to the less developed southeast regions, Mexico is a diverse and heterogeneous country in terms of its socioeconomic and environmental conditions. To give an appropriate view of the research performed on agricultural sustainability in different regions of Mexico, a review by region was established under a socioeconomic criterion proposed by the Ministry of Tourism in Mexico SECTUR (2019): In Figure 1, the regions of Mexico have been organized into eight state clusters for demographic and policy development purposes: i) Northwest, ii) Northeast, iii) West, iv) Central North, v) Central South, vi) East, vii) Southwest and viii) Southeast (SECTUR, 2019). These regions have been taken into account to create a view of sustainability in the different local contexts and the perspectives of agriculture production in Mexico. The research background referred to each region to illustrate the perspectives of research on agricultural sustainability.

Northwest Region
The northwest region includes Baja California, Baja California Sur, Sonora, Chihuahua, Durango, and Sinaloa. In this region of Mexico, the most relevant research problem has been related to water availability issues not only because this region is an arid zone with serious problems of water scarcity but also because the aquifers have been overexploited. The agricultural production of low-value and high water consumption has also been criticized (Salazar-Adams et al., 2012).
The water scarcity conditions worsen along the Baja California Peninsula. Nonetheless, the relevant agroecological sustainability indicators, such as environmental factors, water, soil, social factors, and production factors, have been evaluated (Alvarez-Morales, 2015). Hydroponic agriculture has been proposed as an alternative to the generalized arid conditions in Mexico under the premise that agriculture technology could contribute to improving the management of land and water resources and creating green environments while reducing emissions (De Anda & Shear, 2017).

Northeast Region
In the northeast region, which includes the states of Tamaulipas, Nuevo León, and Coahuila, agroindustries proliferate, and the business perspective is dominant over the research background. The understanding of sustainability from the agroindustrial perspective in Monterrey (Capital City of Nuevo Leon) has recently focused not only on its reduction of emissions and renewable energy development (Meneses-Jácome et al., 2016) but also on organizational initiatives such as green supply chains and green human capital (Rodríguez-Pérez et al., 2021).
Coahuila has one of the most important dairy industries in the country. There, some sustainability evaluations of the production systems have been developed (Próspero-Bernal et al., 2015) as well as about the socioenvironmental impacts of water management in zones with water scarcity such as Cuatro Ciénegas. In González, Tamaulipas, the attitudes of farmers toward natural resource conservation were analyzed to develop efficient public policies and actions (Cruz-Delgado, 2020).

Western Region
The western region of Mexico includes Jalisco, Nayarit, Colima and Michoacan. Jalisco is the most important agave producer in Mexico. There, models of strategic planning with a sustainability approach have been proposed for El Grullo, Autlan, and El Limon Valley (Gómez-López et al., 2018). Other authors have analyzed the driving forces of environmental pressures and responses in forest and agricultural management for sustainability in Cihuatlan municipality (Vásquez-Valencia & García-Almada, 2018) as well as a three-dimensional sustainability assessment tool to evaluate municipalities (Jalil et al., 2020).
In the evaluation of agricultural practices, recent results in Michoacan showed that organic management shows the best results in soil quality and biodiversity management because of the practices and structure of its orchards (Ordaz-Gallegos et al., 2020). Sustainability assessment was also explored in western Mexico through an adapted sustainability framework for proper application and interpretation (Calleros-Islas, 2019).

Central North Region
The central north region includes the states of Zacatecas, San Luis Potosí, Aguascalientes, Guanajuato and Querétaro. Recent findings show the benefits of the organization's capacities for water management in the agricultural systems of southern Guanajuato (Mazabel & Caldera, 2018). Some others recognize that the implementation of an environmental management system would be beneficial for horticultural production in the semiarid context of Zacatecas (Padilla-Bernal et al., 2016).
The social conditions of the central north region of Mexico are more complex than those of the northern regions. The incorporation of the capitalist mode of agricultural production in rural areas has caused the loss of traditional activities. Community participation has been analyzed since the implementation of new public policies in Aguascalientes (Palafox-Muñoz et al., 2016).

Central South Region
The central southern region of Mexico includes the State of Mexico, Morelos, and Mexico City. Although Michoacan is the most important producer of avocado in the country, recent research has focused on its production in Morelos. Under the premise that due to the exponential growth of the productive value of the avocado, it is urgent to create sustainable agriculture measures to maintain competitiveness, Gallegos-Hernández (2019) proposes a state-level development program for the avocado agriculture system.
More than 10% of the whole population of Mexico is located in the metropolitan area of Mexico City. In this urban and overpopulated context, certain initiatives of urban agriculture are still being performed, such as the chinampas systems, an ancient technique with agroecological implications, which have represented the foundations of local socioeconomic strategies (Torres-Lima et al., 1994). The economic, ecological, and social implications of urban agricultural development in Mexico City have also been evaluated (Dieleman, 2017).

Eastern Region
The eastern region of Mexico includes Hidalgo, Tlaxcala, Puebla, and Veracruz. From this point, tropical agroecosystems are located in the southern regions of Mexico. Coffee production has traditionally been recognized in Veracruz and recently in Puebla's Highlands. In Cuetzalan, Puebla and Huatusco and the Cordoba region of Veracruz, agroecosystems have been studied for their integration into organic and fair trade programs (Escamilla-Prado et al., 2005). Coffee rust (Hemileia vastatrix) has been one of the main reasons for the coffee production drop in Latin America. Public policy initiatives have been proposed to attend to both certification and coffee rust issues under the premise that planned actions promote agriculture sustainability (Renard-Hubert & Larroa-Torres, 2017).

Southwest Region
In the southwest region, coffee rust has also been identified as the core challenge to attaining sustainability. In Guerrero, the coffee rust management program for sustainability was developed under an organizational social responsibility approach In Oaxaca, cooperative production has been analyzed in terms of certification achievement and contributions to local sustainability (Montgomery, 2019), as well as provisioning measures by social organizations for sustainability and the promotion of local producers (Ortiz-Ayala et al., 2018).
The background previously detailed served to give an idea of the agriculture and coffee systems approaches in sustainability in Mexico through a division by economic regions and further contrast these conditions to those of the regions where the coffee agroecosystems are located.
As stated before, the coffee production of Mexico is generally located in the southern and eastern regions, where there are common patterns of culture, worldview and indigenous communities as well as ecosystemic conditions that make possible the development of coffee production systems.

Southeast Region
The southeast region, which includes the Yucatan Peninsula states Quintana Roo, Yucatan, Campeche, and Tabasco, is characterized by a low-altitude landscape with a natural tropical forest (80% of the land cover) (Ramirez-Delgado et al., 2015). Due to the physiographic conditions in this region, the agricultural sustainability literature background relates to climate vulnerability and agricultural policies for maize production (Mardero et al., 2018), the sustainable management of coastal ecosystems (Herrera-Silveira et al., 2019) and private property land tenure impacts on deforestation and conservation strategies for forest cover (Ellis et al., 2017).
In this region, some authors have focused on the evaluation of palm oil agroecosystems under a local development and sustainability framework (Márquez et al., 2019) the negative impacts of transgenic soybean production and intensive glyphosphate use on local sustainability have also been analyzed (Rivera de la rosa & Ortiz-Pech, 2017), and the rural development policy for communities in natural protected areas for local environmental management has been implemented (Reyes-Grande, 2015). The agroecosystems in the southeast region have been analyzed with sustainability indices, diagnoses, schemes, and case study methodologies (Martinez-Castro et al., 2015).

The coffee systems in México
There is a great diversity of coffee (Coffea spp.) varieties in Mexico, of which Coffea arabica L. and Coffea Canephora are the most commercially important. For instance, there is a coffee collection at the Mexican National Bank of Coffee Germplasm where 87 accessions were genotypically characterized by the DArTseqTM method and SNP markers in Huatusco, Veracruz (Spinoso-Castillo et al., 2020). There are also mappings of green product development opportunities (Pérez-Hernández et al., 2021) and specialty coffee shop supply chains (Servín-Juárez et al., 2021).
Along with the huge ecosystemic and climate diversity of the Mexican territory, there are agroclimatic zones suitable for coffee production generally located in the southwest of the country, as well as on the border with Guatemala (Bunn et al., 2019). The coffee systems of Mexico are located only in the iii) west, iv) central south, v) central south, vi) east, and vii) southwest regions of Mexico, as shown in Figure 2:

Western Region
The agroecosystems of the western region are located from Talpa de Allende (Ruiz-Palomino et al., 2019) to Sierra de Manantitlán (Moguel & Toledo, 1999) in Jalisco, in Comala and Minatitlan, Colima (Perez et al., 2014), and in the coast region of Michoacan, where some reduction in coffee land cultivation has occurred (Nestel, 1995).
In Michoacan, the ethnoecological perspective suggests that local knowledge has the potential for the development of management strategies and conservation of the species (Castro-Sánchez et al., 2019). Recent studies suggest that the implementation of a planned supply chain with ecological and human dimensions could improve sustainability in avocado production in Michoacan (Denvir et al., 2021), which is taking more relevance in this region than that of coffee.
In this region, there are examples of sustainabilityfocused initiatives, such as The Network for Sustainable Agricultural Alternatives (RASA in its Spanish acronym) founded in 1999, which gathers growers, indigenous people, women, consumers, technical advisors, NGOs, urban population, and universities throughout 20 localities and municipalities of Jalisco to encourage agroecology and popular education of rural households for sustainability (Toledo & Barrera-Bassols, 2017).
There is a difference between peasant and indigenous communities in terms of knowledge, community organization, and community institutional frameworks. In Michoacan, community organizations including both peasant and indigenous communities have generated alternative results in terms of solving contamination problems and the overexploitation of water (Sandoval-Moreno, 2015). The indigenous perspective of agriculture and sustainability strengthens in the southern and eastern regions of Mexico.

Central North Region
This region has a relevant agroclimatic zone in the Sierra Gorda of Queretaro and Guanajuato, as well as the Huasteca Region of San Luis Potosi. There are traditional agroforestry systems in Sierra . The Biosphere Innovation System is part of a global project started by UNESCO, in which the Sierra Gorda, the Yayu coffee forest in Ethiopia, and the Lake Vänern archipelago in Sweden will develop models that can be applied in other parts of the world to promote societal entrepreneurship in biosphere reserves (Bergstrand et al., 2011).

Central South Region
In the central south region, which is Mexico City and surrounding states, there are climatic conditions for coffee production in the State of Mexico as well as Mexico City (Bunn et al., 2019). The wetlands of Xochimilco have been traditionally studied since this is one of the remaining sites where agricultural activities are still performed in the urban context of Mexico City. The chinampas traditional agricultural system has been analyzed in terms of environmental and socioeconomic sustainability (Merlín-Uribe et al., 2013), its potential for resilience by an adaptative cycle analysis for urban sustainability , and restoration practices for the ecosystem for water quality (Zambrano et al., 2020).
In Morelos, empirical studies acknowledge that the cultural diversity of traditional coffee plantations is important for agricultural production (Castro-Rodríguez, 2019). Coffee production seems to be more relevant in the south of the State of Mexico since the coffee of Temascaltepec was recognized as one of the best coffees in Mexico (Alliance for coffee excellence, 2018). Although there are records of nontimber forest product implementation to promote sustainability in these regions (Anastacio-Martínez et al., 2016), research on coffee agroecosystems and their sustainability factors seems to be weak in the region.

Eastern Region
This region, including Hidalgo, Puebla, Tlaxcala, and Veracruz, is gaining relevance due to its coffee production quality and particularities. The Xalapa/ Coatepec region of Veracruz has been a regional leader in quality coffee worldwide, recognized by the Research Institute for Cocoa and Coffee (IRCC Acronym in French) and the Daily Subsistence Allowance (DSA) program, developing a project for the modernization of coffee production systems for intensification, diversification and commercialization improvement (Sallee et al., 1990). Recent studies have characterized the biophysical and structural composition of coffee agroecosystems (Ruiz-García et al., 2020), with carbon storage being a key point for adaptation and mitigation of climate change impacts in the region (Ortiz-Ceballos et al., 2020).
Recent investigations on sustainability have focused on coffee shade canopy plantations for forest management with native species in Hidalgo (Suárez-Islas et al., 2020), on environmental education through community programs in a highdiversity shade coffee-producing region, Cuetzalan (Andresen et al., 2020), and on the diversity of cropping systems and the agroecological transition in the Sierra Norte of Puebla, where diversity of farming management was identified, and local resources and sociotechnical practices lead to a favorable state of the agroecological transition (Espidio-Balbuena et al., 2020).

Southwest region
The southwest region of Mexico includes the states of Guerrero, Oaxaca, and Chiapas. In this socially and eco-systemically diverse context, the vulnerability of coffee systems comes to the fore as a core topic in sustainability analyses.
Recent findings suggest that the agroecological collective practices of indigenous organizations strengthen social capital, adaptability, and natural resource conservation in Guerrero (Galicia-Gallardo et al., 2021). Other socioeconomic perspectives suggest that in Oaxaca, there are communitybased responses to climate change. There are areas with high slopes and marginalization showing deforestation patterns and others with reforestation trends where local communities are a relevant bottom-up driver of change in natural resource conservation (Novotny et al., 2021). The suitability of the land to grow coffee is currently being analyzed in the Mixteca Alta region of Oaxaca to map the local knowledge perspectives on agriculture through geographic information systems (López-Carmona et al., 2021).
There are recent findings regarding traditional knowledge of edible plants from the indigenous communities of the Sierra Norte of Oaxaca, where this knowledge is essential for the conservation, use, and management of local plant diversity (Pascual-Mendoza et al., 2021).
There is statistical evidence that the coffee growers in Chiapas better adopt emerging technologies throughout a whole supply chain focus. This can improve sustainable practices such as resistant variety crops, pest management, soil analysis, water conservation and harvesting (Contreras-Medina et al., 2020).
In Chiapas, there are local supply chains of coffee looking for global expansion. Coffee entrepreneurs and their collective organizations have established alliances with transnational actors (Espinosa-Gallegos et al., 2021).
While the central north and central south regions have the least proper conditions for coffe production, they are developing several practices for sustainability and environmental protection. In the western region, producers are coping with expanding avocado systems, and some indigenous community organizations are trying to maintain coffee systems.
The only regions where coffee production is maintaining or expanding are the eartern and southwest regions, where we find more cases of sustainability studies and communities with coffee systems.

The thresholds of sustainability research at the local scale
The sustainability research perspectives applied to the coffee systems in Mexico are in continuous change because of the environmental, social, economic and cultural heterogeneity of the coffee-producing regions of Mexico. This review identifies five perspectives as the thresholds of research applied to coffee system sustainability: 1) Local knowledge and community-based coffee systems (Novotny et al., 2021) Table 1: The sustainability perspectives integrate diverse topics, including the economic, environmental, social, cultural and institutional dimensions of coffee production in Mexico.
Local knowledge relates to sustainability because the local rules for land planning and natural resource management bring out patterns of local governance and support for sustainable landscape change (Novotny et al., 2021). Sustainable practices can also improve the coffee supply chain based on certain emerging technologies (Contreras-Medina et al., 2020) VOLUME 50 Nº2 MAY -AUGUST 2023 Women's participation in coffee production promotes organizational governance (Lyon, 2019) and is very relevant in organizations with self-management, organizational capacity, and solidarity to address sustainability (Merlín-Uribe et al., 2019).
The agroecology perspective has a lack of information regarding biophysical and physiographic factors of the arboreal structure and soil composition, which define agroecosystem management, improvement and conservation (Ruiz-García et al., 2020).

Conclusions
The objective of this paper was to integrate a review of relevant research to identify the different local-scale approaches of agriculture sustainability in different regions of Mexico to finally apply this investigation to coffee systems as a system with sustainability potential (Perfecto & Vandermeer, 2015).
Although the thresholds of sustainability research on coffee systems have common factors of analysis, because they generally start from the intersection of environmental, social, and economic factors (Elkington, 1997), there will always be different local conditions that define sustainability studies beyond the available theoretical or conceptual considerations in the literature. Additionally, to determine the proper definition of sustainability for a certain context, it is necessary to consider normative, methodological and philosophical considerations (Dietz et al., 2018), as well as the heterogeneity of the producers' conditions in each context (Guadarrama-Zugasti, 2008).
This paper illustrates the sustainability of Mexico's agriculture from the perspective of each region of the country through the particularities of the coffee systems. This analysis also allows us to acknowledge that the three spheres of environmental, social and economic factors are valid and represent the base for the most recent investigations on coffee system sustainability. Social factors seem to be the most complex and discussed considerations in the analyzed literature because Latin American environmental thinking acquires its identity from the cultural heritage of its peoples (Leff, 2012).
As we can see, the environmental, social and economic conditions allow coffee system development in six of the eight regions of Mexico. In the northern regions, where physiographic conditions do not allow coffee production, there are agroindustries and capital. Meanwhile, in the southern and eastern regions, social, economic and cultural factors allow the development of social and rural collective organizations for coffee production.
Although there are common characteristics and conditions throughout Mexican coffee production systems, it is necessary to recognize the relevance of local knowledge to improve agricultural practices in each context, even in areas with high levels of ecological degradation (López-Carmona et al., 2021). Local knowledge is an expression of growers' thinking, and it is important for the interpretation of the local processes of agriculture. It represents a key point to integrate working hypotheses formulation into coffee system sustainability research.
Although there are political agreements and sustainability assessment frameworks, most of these approaches are integrated from theoretical interpretations, and local communities establish drivers of change for natural resource management (Novotny et al., 2021). The explicative potential of the local factors lies not only under the premise that there is a close relationship between agriculture and the natural environment but also on the local heterogeneity of the environmental, social, economic, institutional and cultural factors.
The thresholds of sustainability research on coffee systems in Mexico go further than the three spheres of the sustainability concept, particularly with local-scale approaches. Local knowledge, community-based strategies and women's participation integrate a cultural sphere of sustainability. The organization for production and adaptation to climate change would be part of the social sphere, while the agroecosystem definition and analysis would be integrated within the environmental issues of sustainability.
The agroecology perspective is relevant because it seeks to integrate agroecosystems from the close interaction of agriculture and ecosystems. It is very important to consider the local culture in terms of knowledge, community-based practices, and land tenure, among other conditions, to develop an appropriate sustainability assessment. An agroecology perspective with an appreciative sense of local heterogeneity would enhance mainstream sustainability research for better interpretation and evaluation.
This analysis allows defining Mexican coffee systems as heterogeneous, with generalized community-based and traditional management oriented to supply chain development, gender equality, climate change adaptation, and agroecosystem development.
The thresholds of sustainability research in coffee systems of Mexico are defined under the heterogeneity of conditions with a high potential to develop further investigations. The agricultural transition and sustainability assessment of coffee systems need to be performed under a contextual view of the phenomenon.
The southwestern and eastern regions are those where the highest number of sustainability studies are being developed. These regions showed an orientation toward community-based systems, the creation of supply chains with a sustainable emphasis and the application of agroecological practices.
With these findings, we were able to identify three of the five thresholds of sustainability research.
The climate change resilience and the womens' participation research lines were also identified in these regions but at a lower scale, with fewer cases than those stated before. It is recommended to develop these research lines in coffee regions, as they are relevant in sustainability studies along other regions in the central and northern regions.
Local-scale sustainability studies are prolific in the central and southern regions, including the western and eastern regions. Due to the local heterogeneity of agricultural systems and their environmental, social and economic factors, local-scale approaches and case analysis are the best way to explain sustainability realities and assess their multidimensional factors. Therefore, we recommend following up with research on a local scale and being careful of the local heterogeneity factors, where qualitative studies and study case methodologies are good choices to perform sustainability studies in agriculture and coffee systems. El concepto de sostenibilidad pretende integrar diversos aspectos de las necesidades humanas mediante el análisis de las dimensiones medioambiental, social y económica. Aunque existe un marcado consenso sobre el concepto de sostenibilidad, existen condiciones locales que definen los patrones de producción y sus condiciones reales de sostenibilidad. Este trabajo pretende integrar una revisión de la investigación sobre sustentabilidad en los sistemas agrícolas de México con un enfoque de

References
Alliance for Coffee Excellence (2018 An adaptive low-input tool applied to the management of agroecosystems in México. Eco-escala local, destacando las perspectivas locales de cada región para ofrecer una visión clara de la totalidad de los sistemas agrícolas del país y encontrar los umbrales de la investigación sobre sustentabilidad en las regiones cafetaleras de México. Para integrar la revisión se utilizaron diversas bases de datos y citas de artículos seleccionados a partir de 2012, con algunas referencias de referencia de 2002, y la estructura del artículo se desarrolló bajo una técnica narrativa. Como resultado, se muestra una visión de los enfoques de investigación en sustentabilidad a diferentes escalas locales en los sistemas agrícolas de México, haciendo énfasis en los sistemas cafetaleros y mostrando los umbrales de la investigación en sustentabilidad con estos enfoques.